Problem: A jar contains $11$ red jelly beans, $9$ green jelly beans, and $3$ blue jelly beans. If a jelly bean is randomly chosen, what is the probability that it is not blue?
Explanation: There are $11 + 9 + 3 = 23$ jelly beans in the jar. There are $3$ blue jelly beans. That means $23 - 3 = 20$ are not blue. The probability is $ \frac{20}{23}$.